The invention relates generally to a medical device, and more particularly to a medicament delivery device for automatically injecting a medicament into a body of a patient.
Exposure to certain substances, such as, for example, peanuts, shellfish, bee venom, certain drugs, toxins, and the like, can cause allergic reactions in some individuals. Such allergic reactions can, at times, lead to anaphylactic shock, which can cause a sharp drop in blood pressure, hives, and/or severe airway constriction. Accordingly, responding rapidly to mitigate the effects from such exposures can prevent injury and/or death. For example, in certain situations, an injection of epinephrine (i.e., adrenaline) can provide substantial and/or complete relief from the allergic reaction. In other situations, for example, an injection of an antidote to a toxin can greatly reduce and/or eliminate the harm potentially caused by the exposure.
Because emergency medical facilities may not be available when an individual is suffering from an allergic reaction, some individuals carry an auto-injector to rapidly self-administer a medicament in response to an allergic reaction.
Some known auto-injectors include a locking cap at the proximal end of the auto-injector to prevent inadvertent actuation and a needle cover at the distal end of the auto-injector. Such a configuration can, at times, cause a user to become confused as to which end of the auto-injector is the “needle end” (i.e., the distal end) and which end of the auto-injector is the “actuation end” (i.e., the proximal end). As such, in some situations, a user may mistakenly actuate the known auto-injector away from the intended injection site. Such an error can result, for example, in the auto-injector being actuated into the user's thumb and/or finger. Furthermore, the locking cap can be removed prior to removal of the needle cover, thus allowing the auto-injector to be actuated before the needle cover has been removed.
Some known auto-injectors include a needle cover that collapses or buckles when the auto-injector is actuated and the needle breaks through the cover. In application, this leaves the needle cover bunched around a portion of the needle, which can cause the needle cover to interfere with penetration of the needle into the user.
Manufacturing techniques of known auto-injectors require much of the manufacturing process of an auto-injector to occur in a sterile environment. In particular, a sterile environment is needed for filling the auto-injector with a medicament and for assembly of the auto-injector. Providing and maintaining a sterile environment during the entire manufacturing process, however, can be quite expensive.
Thus, a need exists for an auto-injector that can be more conveniently carried by a user and that can be actuated from its distal end. A need exists for an auto-injector that cannot be actuated until the needle cover has been removed. A need also exists for an auto-injector with a needle cover that will not interfere with, but will ensure, consistent penetration of the needle. Furthermore, a need exists for a more economical method of manufacturing auto-injectors.